US5410747A - Dual conversion transmitter - Google Patents

Dual conversion transmitter Download PDF

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Publication number
US5410747A
US5410747A US08/092,667 US9266793A US5410747A US 5410747 A US5410747 A US 5410747A US 9266793 A US9266793 A US 9266793A US 5410747 A US5410747 A US 5410747A
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United States
Prior art keywords
signal
frequency
local oscillation
produce
mixing
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Expired - Fee Related
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US08/092,667
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English (en)
Inventor
Shinichi Ohmagari
Osamu Yamamoto
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NEC Corp
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NEC Corp
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J3/00—Continuous tuning
    • H03J3/28—Continuous tuning of more than one resonant circuit simultaneously, the tuning frequencies of the circuits having a substantially constant difference throughout the tuning range
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D7/00—Transference of modulation from one carrier to another, e.g. frequency-changing
    • H03D7/16—Multiple-frequency-changing
    • H03D7/161—Multiple-frequency-changing all the frequency changers being connected in cascade
    • H03D7/163—Multiple-frequency-changing all the frequency changers being connected in cascade the local oscillations of at least two of the frequency changers being derived from a single oscillator
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B21/00—Generation of oscillations by combining unmodulated signals of different frequencies
    • H03B21/01—Generation of oscillations by combining unmodulated signals of different frequencies by beating unmodulated signals of different frequencies
    • H03B21/02—Generation of oscillations by combining unmodulated signals of different frequencies by beating unmodulated signals of different frequencies by plural beating, i.e. for frequency synthesis ; Beating in combination with multiplication or division of frequency
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J1/00—Details of adjusting, driving, indicating, or mechanical control arrangements for resonant circuits in general
    • H03J1/0008—Details of adjusting, driving, indicating, or mechanical control arrangements for resonant circuits in general using a central processing unit, e.g. a microprocessor

Definitions

  • the present invention relates to a transmitter and, more particularly, to a transmitter of the type using a dual conversion system which subjects a modulated signal to frequency conversion twice to produce a high frequency signal to be transmitted.
  • a transmitter using a dual conversion system is disclosed in, for example, Japanese Patent Publication No. 43609/1987 (JP-B2-62-43609).
  • the transmitter disclosed in this Patent Publication has a single local oscillator. Specifically, one of two frequency converters is supplied with a local oscillation signal from the single local oscillator while the other is supplied with a multiplied local oscillation signal. Such a single local oscillator scheme is successful in reducing the circuit scale of a transmitter.
  • VSAT very small aperture terminal
  • a frequency band to be used is allocated beforehand.
  • the allocated frequency band is subdivided into a plurality of frequency bands, and each of such frequency bands is assigned to a respective one of VSAT station.
  • a hub station sometimes control the frequency band assigned to each VSAT station, depending on the traffic. Therefore, each VSAT station has a variable frequency local oscillator so that the transmission signal frequency may be varied beforehand.
  • the conventional transmitter using a dual conversion system and having a single local oscillator as stated earlier is applicable to the VSAT system.
  • a modulated signal from an indoor unit (IDU) which includes a modulating section is inputted to an outdoor unit (ODU) by a cable. Since the cable loss increases with the increase in the frequency of the modulated signal which is propagated through the cable, the frequency of the modulated signal should preferably be low.
  • the leakage component of the local oscillation signal has a frequency close to the frequency of a frequency-converted intermediate frequency (IF) signal, as will be described later in detail.
  • the frequency of the frequency-converted IF signal is close to the frequencies of spurious components.
  • band pass filter having a broad pass band, so that a plurality of frequency bands may be used. It follows that the band pass filter connected to the output of the frequency converter and having a fixed band width has to have a sharp cut-off characteristic at the outside of the band. However, a band pass filter with a sharp cut-off characteristic is expensive and, moreover, difficult to produce.
  • a transmitter has a voltage controlled filter connected to the output of a mixer which mixes a modulated signal or first IF signal and a local oscillation signal to produce a second IF signal.
  • the center frequency of the voltage controlled filter is varied in matching relation to the frequency of the local oscillation signal.
  • the transmitter removes unnecessary components close to the frequency of the second IF signal by means of a variable frequency band pass filter which does not need to have a sharp cut-off characteristic at the outside of the band.
  • FIG. 1 is a block diagram schematically showing a transmitter embodying the present invention
  • FIGS. 2A & 2B show the frequency arrangement of input and output signals of various circuits shown in FIG. 1;
  • FIG. 3 shows the frequency arrangement of a plurality of first IF signals.
  • a transmitter embodying the present invention is shown and generally made up of an IDU 100, a cable 103, an ODU 110, and an antenna 123. The operation of the embodiment will be described with reference also made to FIG. 2.
  • a modulator 101 modulates a carrier wave from a local oscillator 102 in response to a data signal by phase modulation or a similar modulation scheme.
  • the resultant modulated signal or first intermediate frequency (IF) signal 1 has a bandwidth of several hundred kHz.
  • the center frequencies of this signal 1 are arranged in a relatively low frequency band of 180 ⁇ 18 MHz and separated by intervals greater than their band width, so that the cable loss of the cable 103 may be reduced. Specifically, as shown in FIG. 3, the lowest center frequency is 162 MHz while the highest center frequency is 198 MHz.
  • the individual IF signals each having a bandwidth of several hundred kHz are arranged separated by interval greater than their bandwidth.
  • the frequency arrangement of the IF signal 1 is represented by a single square, and only the minimum and maximum center frequencies are shown with the band widths omitted. The following description will also concentrate on the center frequencies.
  • the cable 103 feeds the first IF signal whose center frequency is f 1 from the IDU 100 to a variable attenuator 111 included in the ODU 110.
  • the variable attenuator 111 controls the amplitude of the first IF signal 1 to a predetermined value to produce an amplitude-controlled first IF signal 2.
  • a first amplifier 112 receives the amplitude-controlled first IF signal 2 and amplifies it to output an amplified first IF signal 3.
  • a variable frequency local oscillator or synthesizer 113 generates first local oscillation (Lo) signals 4.
  • the first Lo signals 4 are arranged in a range of 2764 to 2864 MHz at an interval of 4 MHz, and one frequency (f LO ) is selected by a first control signal 5 fed to the synthesizer 113 from a controller 114.
  • a first mixer 115 mixes the amplified first IF signal 3 and first Lo signal 4 to produce a second IF signal 6 whose center frequency is f 1 +f LO .
  • the second IF signal 6 lies in the range of 2926 to 3062 MHz.
  • the first mixer 6 outputs the leakage component f LO of the first Lo signal and spurious components together with the second IF signal 6.
  • spurious components close to the frequency band of the second IF signal 6 they may include the mixture of a signal having double the frequency of the first IF signal and the first Lo signal, i.e., f LO +2f 1 (3088 to 3260 MHz).
  • a voltage controlled filter (V.C.F) 116 removes such leakage components and spurious components.
  • the V.C.F 116 has the center frequency of its pass band controlled by a second control signal 7 fed from the controller 114. Assuming that the frequency of the first Lo signal 4 is controlled to 2764 MHz by the first control signal 5 from the controller 114, then the center frequency of the second IF signal 6 is in the range of (2944-18) to (2944+18) MHz.
  • the pass band of the V.C.F 116 is also controlled to be 2944 ⁇ 18 MHz by the second control signal 7 from the controller 114. Since the pass band of the V.C.F 116 is sufficiently remote from the center frequency (2764 MHz) of the leakage components of the first Lo signals 4 and the spurious components (3088 to 3160 MHz), the cut-off characteristic of the V.C.F 116 for the outside of the band does not have to be sharp.
  • the center frequency of the second IF signal 6 is in the range of (2948-18) to (2948+18) MHz.
  • the pass band of the V.C.F 116 is controlled to 2948 ⁇ 18 MHz.
  • the center frequency of the second IF signal 6 is in the range of (3044-18) to (3044+18) MHz.
  • Such a pass band (3026 to 3062 MHz) is sufficiently remote from the leakage components (2864 MHz) of the first Lo signals and the spurious components (3188 to 3260 MHz).
  • the spurious components occur in a range of 3124 ⁇ 36, 3128 ⁇ 36, and 3224 ⁇ 36 MHz under the above conditions.
  • the pass band of the V.C.F 116 is variable in matching relation to the frequency of the first Lo signal 4.
  • B.P.F. band pass filter
  • the pass band of the B.P.F. is fixed at 2926 to 3062 MHz with no regard to the frequency of the Lo signal.
  • spurious components (3088 to 3160 MHz) appearing when the frequency of the Lo signal is 2764 MHz, and the leakage component appearing when it is 2864 MHz, are close to the pass band of the B.P.F.
  • Such spurious components or leak components cannot be removed unless the B.P.F. has a sharp cut-off characteristic for the outside of the band.
  • a filter with a sharp cut-off characteristic is expensive and difficult to produce.
  • the illustrative embodiment changes the pass band of the V.C.F. 116, whose pass band width is identical with the frequency band width of the modulated signal or first IF signal, in matching relation to the frequency of the first Lo signal. This is successful in removing the spurious components and leakage components even if the filter does not have a sharp cut-off characteristic.
  • a second amplifier 117 receives the second IF signal 8 from the V.C.F. 116 and from which unnecessary components have been removed, and amplifies it to output an amplified second IF signal 9.
  • a multiplier 118 multiplies the frequency of the input signal by N (integer greater than 1). Generally, the construction of a multiplier is simpler when N is an even number than when it is an odd number, as well known in the art.
  • the band width necessary for a plurality of second IF signals should be broadened, resulting in the increase in the band width of the V.C.F.
  • the integer N should be 4.
  • the multiplier 118 multiplies the first Lo signal 4 by 4 to produce a second Lo signal 10 whose frequency ranges from 11056 to 11456 MHz.
  • a third amplifier 119 amplifies the second Lo signal 10 to output an amplified second Lo signal 11.
  • a second mixer 120 mixes the amplified second IF signal 9 and amplified second Lo signal 119, thereby producing a high frequency transmission signal (RF signal) 12.
  • the frequency of the RF signal 12 is 13982 to 14518 MHz.
  • a band pass filter (B.P.F.) 121 has a pass band of 13982 to 14518 MHz for thereby removing unnecessary components other than the RF signal 12. Since the unnecessary components, i.e., the leakage components of the second Lo signals and the spurious components, are remote from the frequency band of the RF signal, it is not necessary to use a V.C.F.
  • a fourth amplifier 122 amplifies the RF signal 13 from the B.P.F. 121 to output an amplified RF signal 14. The amplified RF signal 14 is radiated from the antenna 123.
  • a voltage controlled filter having a variable center frequency is connected to the output of a mixer which mixes a modulated signal or first IF signal and a local oscillation signal from a synthesizer to thereby produce a second IF signal.
  • the center frequency of the voltage controlled filter is varied in matching relation to the frequency of the local oscillation signal, whereby spurious components and leakage components close to the frequency of the second IF signal are removed.
  • the present invention implements an inexpensive transmitter since the voltage controlled filter does not have to have a sharp cut-off characteristic at the outside of the band.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Transmitters (AREA)
US08/092,667 1990-07-31 1993-07-14 Dual conversion transmitter Expired - Fee Related US5410747A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US08/092,667 US5410747A (en) 1990-07-31 1993-07-14 Dual conversion transmitter

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2201129A JP2595783B2 (ja) 1990-07-31 1990-07-31 送信器
JP2-201129 1990-07-31
US73885391A 1991-07-31 1991-07-31
US08/092,667 US5410747A (en) 1990-07-31 1993-07-14 Dual conversion transmitter

Related Parent Applications (1)

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US73885391A Continuation 1990-07-31 1991-07-31

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US5410747A true US5410747A (en) 1995-04-25

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Country Status (6)

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US (1) US5410747A (ja)
EP (1) EP0469898B1 (ja)
JP (1) JP2595783B2 (ja)
AU (1) AU635147B2 (ja)
CA (1) CA2048148C (ja)
DE (1) DE69118045T2 (ja)

Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5754949A (en) * 1995-03-27 1998-05-19 Fujistu Limited Transmitter-receiver apparatus
US5784413A (en) * 1996-09-06 1998-07-21 General Instrument Corporation Direct digital synthesis frequency-agile QPSK modulator
US5794131A (en) * 1996-03-19 1998-08-11 Ericsson Inc. Reducing or eliminating radio transmitter mixer spurious outputs
US5924024A (en) * 1996-05-15 1999-07-13 Shinko Electric Industries, Co., Ltd. Method and circuit for achieving frequency conversion
US5924021A (en) * 1996-09-03 1999-07-13 Raytheon Company Frequency conversion circuit and method for millimeter wave radio
US5963852A (en) * 1997-03-24 1999-10-05 Ericsson Inc. Dual band mobile station
US5995812A (en) * 1995-09-01 1999-11-30 Hughes Electronics Corporation VSAT frequency source using direct digital synthesizer
US6097765A (en) * 1995-09-05 2000-08-01 Hughes Electronics Corporation Method and apparatus for performing digital fractional minimum shift key modulation for a very small aperture terminal
WO2000051371A1 (en) * 1999-02-23 2000-08-31 Conexant Systems, Inc. System and process for shared functional block communication transceivers with gps capability
US6304216B1 (en) 1999-03-30 2001-10-16 Conexant Systems, Inc. Signal detector employing correlation analysis of non-uniform and disjoint sample segments
US6327471B1 (en) 1998-02-19 2001-12-04 Conexant Systems, Inc. Method and an apparatus for positioning system assisted cellular radiotelephone handoff and dropoff
US6343221B1 (en) * 1996-12-10 2002-01-29 Fujitsu Limited Digital portable telephone device
WO2002011470A1 (en) * 2000-08-02 2002-02-07 Conexant Systems, Inc. Block communication transceivers with gps capability
US6348744B1 (en) 1998-04-14 2002-02-19 Conexant Systems, Inc. Integrated power management module
US20020111145A1 (en) * 2001-02-15 2002-08-15 Jean-Luc Robert Variable-power transceiving device
US6448925B1 (en) 1999-02-04 2002-09-10 Conexant Systems, Inc. Jamming detection and blanking for GPS receivers
US6496145B2 (en) 1999-03-30 2002-12-17 Sirf Technology, Inc. Signal detector employing coherent integration
US6519277B2 (en) 1999-05-25 2003-02-11 Sirf Technology, Inc. Accelerated selection of a base station in a wireless communication system
US6531982B1 (en) 1997-09-30 2003-03-11 Sirf Technology, Inc. Field unit for use in a GPS system
US6606349B1 (en) 1999-02-04 2003-08-12 Sirf Technology, Inc. Spread spectrum receiver performance improvement
US6693953B2 (en) 1998-09-30 2004-02-17 Skyworks Solutions, Inc. Adaptive wireless communication receiver
US6714158B1 (en) 2000-04-18 2004-03-30 Sirf Technology, Inc. Method and system for data detection in a global positioning system satellite receiver
US6778136B2 (en) 2001-12-13 2004-08-17 Sirf Technology, Inc. Fast acquisition of GPS signal
US6788655B1 (en) 2000-04-18 2004-09-07 Sirf Technology, Inc. Personal communications device with ratio counter
US20050025222A1 (en) * 1998-09-01 2005-02-03 Underbrink Paul A. System and method for despreading in a spread spectrum matched filter
US6931055B1 (en) 2000-04-18 2005-08-16 Sirf Technology, Inc. Signal detector employing a doppler phase correction system
US20050209762A1 (en) * 2004-03-18 2005-09-22 Ford Global Technologies, Llc Method and apparatus for controlling a vehicle using an object detection system and brake-steer
US6952440B1 (en) 2000-04-18 2005-10-04 Sirf Technology, Inc. Signal detector employing a Doppler phase correction system
US7711038B1 (en) 1998-09-01 2010-05-04 Sirf Technology, Inc. System and method for despreading in a spread spectrum matched filter
US20100117693A1 (en) * 2008-11-07 2010-05-13 Viasat, Inc. Dual conversion transmitter with single local oscillator
WO2010082957A1 (en) * 2009-01-19 2010-07-22 Skyworks Solutions, Inc. Programmable transmit continuous-time filter
US7885314B1 (en) 2000-05-02 2011-02-08 Kenneth Scott Walley Cancellation system and method for a wireless positioning system
TWI502926B (zh) * 2013-08-05 2015-10-01 Hon Hai Prec Ind Co Ltd 雙工器及使用該雙工器的線纜數據機

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5930688A (en) * 1992-04-02 1999-07-27 Stanford Telecommunications, Inc. Method and apparatus for intermodulation noise suppression in RF power amplifiers
WO1996042134A1 (fr) * 1995-06-09 1996-12-27 Matsushita Electric Industrial Co., Ltd. Amplificateur
US5732330A (en) * 1996-07-02 1998-03-24 Ericsson Inc. Dual band transceiver
US6091939A (en) * 1997-02-18 2000-07-18 Ericsson Inc. Mobile radio transmitter with normal and talk-around frequency bands
GB9804708D0 (en) * 1998-03-05 1998-04-29 Nec Technologies Uk Ltd Radio transmitter/reciever channel selection
JP2000068886A (ja) 1998-08-19 2000-03-03 Matsushita Electric Ind Co Ltd 受信装置および送受信装置
WO2000028664A2 (en) 1998-11-12 2000-05-18 Broadcom Corporation Fully integrated tuner architecture
GB0025902D0 (en) * 2000-10-23 2000-12-06 Simoco Int Ltd Radio transmitters
JP5808644B2 (ja) * 2011-10-26 2015-11-10 シャープ株式会社 受信装置および通信システム
JP6009251B2 (ja) * 2012-07-13 2016-10-19 シャープ株式会社 ミリ波送信モジュール、およびミリ波送信装置

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4025855A (en) * 1976-04-30 1977-05-24 General Aviation Electronics, Inc. Multi-channel R.F. transducer with channel selector coupled to selected channel filter
US4262361A (en) * 1979-06-29 1981-04-14 Edmac Associates, Inc. Variable bandwidth filtering and frequency converting system
US4322995A (en) * 1979-06-07 1982-04-06 Tavel Donald L Music synthesizer
US4458207A (en) * 1980-09-16 1984-07-03 Thomson-Csf FM Demodulator with variable bandpass filter
US4581643A (en) * 1983-07-25 1986-04-08 Rca Corporation Double conversion television tuner with frequency response control provisions
JPS6243609A (ja) * 1985-08-22 1987-02-25 Matsushita Electric Ind Co Ltd 光回路素子
US5027430A (en) * 1987-07-24 1991-06-25 Sharp Kabushiki Kaisha Outdoor unit low noise converter for satellite broadcast reception use

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50158211A (ja) * 1974-06-10 1975-12-22
DE2547092C3 (de) * 1975-10-21 1983-05-05 Siemens AG, 1000 Berlin und 8000 München Zwischenfrequenzumsetzer
JPS556980A (en) * 1978-06-30 1980-01-18 Fujitsu Ltd Local oscillator for multiple radio unit
JPS6188345U (ja) * 1984-11-14 1986-06-09
DE3505183A1 (de) * 1985-02-15 1986-11-27 Loewe Opta Gmbh, 8640 Kronach Frequenzumsetzer fuer gemeinschaftsantennenanlagen und kabelverteilnetze mit einem eingangsumsetzer und einem ausgangsumsetzer
GB2181312A (en) * 1985-10-01 1987-04-15 Plessey Co Plc Frequency alignment circuit and synthesizer therefor

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4025855A (en) * 1976-04-30 1977-05-24 General Aviation Electronics, Inc. Multi-channel R.F. transducer with channel selector coupled to selected channel filter
US4322995A (en) * 1979-06-07 1982-04-06 Tavel Donald L Music synthesizer
US4262361A (en) * 1979-06-29 1981-04-14 Edmac Associates, Inc. Variable bandwidth filtering and frequency converting system
US4458207A (en) * 1980-09-16 1984-07-03 Thomson-Csf FM Demodulator with variable bandpass filter
US4581643A (en) * 1983-07-25 1986-04-08 Rca Corporation Double conversion television tuner with frequency response control provisions
JPS6243609A (ja) * 1985-08-22 1987-02-25 Matsushita Electric Ind Co Ltd 光回路素子
US5027430A (en) * 1987-07-24 1991-06-25 Sharp Kabushiki Kaisha Outdoor unit low noise converter for satellite broadcast reception use

Cited By (54)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5754949A (en) * 1995-03-27 1998-05-19 Fujistu Limited Transmitter-receiver apparatus
US5995812A (en) * 1995-09-01 1999-11-30 Hughes Electronics Corporation VSAT frequency source using direct digital synthesizer
US6370204B1 (en) 1995-09-05 2002-04-09 Hughes Electronics Corporation Method and apparatus for performing digital fractional minimum shift key modulation for a very small aperture terminal
US6097765A (en) * 1995-09-05 2000-08-01 Hughes Electronics Corporation Method and apparatus for performing digital fractional minimum shift key modulation for a very small aperture terminal
US5794131A (en) * 1996-03-19 1998-08-11 Ericsson Inc. Reducing or eliminating radio transmitter mixer spurious outputs
US5924024A (en) * 1996-05-15 1999-07-13 Shinko Electric Industries, Co., Ltd. Method and circuit for achieving frequency conversion
US5924021A (en) * 1996-09-03 1999-07-13 Raytheon Company Frequency conversion circuit and method for millimeter wave radio
US5784413A (en) * 1996-09-06 1998-07-21 General Instrument Corporation Direct digital synthesis frequency-agile QPSK modulator
US6751471B2 (en) 1996-12-10 2004-06-15 Fujitsu Limited Digital portable telephone device
US6343221B1 (en) * 1996-12-10 2002-01-29 Fujitsu Limited Digital portable telephone device
US5963852A (en) * 1997-03-24 1999-10-05 Ericsson Inc. Dual band mobile station
US6531982B1 (en) 1997-09-30 2003-03-11 Sirf Technology, Inc. Field unit for use in a GPS system
US6327471B1 (en) 1998-02-19 2001-12-04 Conexant Systems, Inc. Method and an apparatus for positioning system assisted cellular radiotelephone handoff and dropoff
US6348744B1 (en) 1998-04-14 2002-02-19 Conexant Systems, Inc. Integrated power management module
US7852905B2 (en) 1998-09-01 2010-12-14 Sirf Technology, Inc. System and method for despreading in a spread spectrum matched filter
US7711038B1 (en) 1998-09-01 2010-05-04 Sirf Technology, Inc. System and method for despreading in a spread spectrum matched filter
US7545854B1 (en) 1998-09-01 2009-06-09 Sirf Technology, Inc. Doppler corrected spread spectrum matched filter
US20050025222A1 (en) * 1998-09-01 2005-02-03 Underbrink Paul A. System and method for despreading in a spread spectrum matched filter
US6693953B2 (en) 1998-09-30 2004-02-17 Skyworks Solutions, Inc. Adaptive wireless communication receiver
US6606349B1 (en) 1999-02-04 2003-08-12 Sirf Technology, Inc. Spread spectrum receiver performance improvement
US6448925B1 (en) 1999-02-04 2002-09-10 Conexant Systems, Inc. Jamming detection and blanking for GPS receivers
WO2000051371A1 (en) * 1999-02-23 2000-08-31 Conexant Systems, Inc. System and process for shared functional block communication transceivers with gps capability
US6208844B1 (en) * 1999-02-23 2001-03-27 Conexant Systems, Inc. System and process for shared functional block communication transceivers with GPS capability
US6577271B1 (en) 1999-03-30 2003-06-10 Sirf Technology, Inc Signal detector employing coherent integration
US6636178B2 (en) 1999-03-30 2003-10-21 Sirf Technology, Inc. Signal detector employing correlation analysis of non-uniform and disjoint sample segments
US6304216B1 (en) 1999-03-30 2001-10-16 Conexant Systems, Inc. Signal detector employing correlation analysis of non-uniform and disjoint sample segments
US6496145B2 (en) 1999-03-30 2002-12-17 Sirf Technology, Inc. Signal detector employing coherent integration
US7002516B2 (en) 1999-03-30 2006-02-21 Sirf Technology, Inc. Signal detector employing correlation analysis of non-uniform and disjoint sample segments
US20050035905A1 (en) * 1999-03-30 2005-02-17 Gronemeyer Steven A. Signal detector employing correlation analysis of non-uniform and disjoint sample segments
US6519277B2 (en) 1999-05-25 2003-02-11 Sirf Technology, Inc. Accelerated selection of a base station in a wireless communication system
US6714158B1 (en) 2000-04-18 2004-03-30 Sirf Technology, Inc. Method and system for data detection in a global positioning system satellite receiver
US20040172195A1 (en) * 2000-04-18 2004-09-02 Underbrink Paul A. Method and system for data detection in a global positioning system satellite receiver
US6788655B1 (en) 2000-04-18 2004-09-07 Sirf Technology, Inc. Personal communications device with ratio counter
US6931055B1 (en) 2000-04-18 2005-08-16 Sirf Technology, Inc. Signal detector employing a doppler phase correction system
US7269511B2 (en) 2000-04-18 2007-09-11 Sirf Technology, Inc. Method and system for data detection in a global positioning system satellite receiver
US6952440B1 (en) 2000-04-18 2005-10-04 Sirf Technology, Inc. Signal detector employing a Doppler phase correction system
US6961660B2 (en) 2000-04-18 2005-11-01 Sirf Technology, Inc. Method and system for data detection in a global positioning system satellite receiver
US20050264446A1 (en) * 2000-04-18 2005-12-01 Underbrink Paul A Method and system for data detection in a global positioning system satellite receiver
US7885314B1 (en) 2000-05-02 2011-02-08 Kenneth Scott Walley Cancellation system and method for a wireless positioning system
WO2002011470A1 (en) * 2000-08-02 2002-02-07 Conexant Systems, Inc. Block communication transceivers with gps capability
US20020111145A1 (en) * 2001-02-15 2002-08-15 Jean-Luc Robert Variable-power transceiving device
US6795691B2 (en) * 2001-02-15 2004-09-21 Thomson Licensing S.A. Variable-power transceiving device
US6778136B2 (en) 2001-12-13 2004-08-17 Sirf Technology, Inc. Fast acquisition of GPS signal
US7999733B2 (en) 2001-12-13 2011-08-16 Sirf Technology Inc. Fast reacquisition of a GPS signal
US20080198069A1 (en) * 2001-12-13 2008-08-21 Gronemeyer Steven A Fast Reacquisition of a GPS Signal
US20050209762A1 (en) * 2004-03-18 2005-09-22 Ford Global Technologies, Llc Method and apparatus for controlling a vehicle using an object detection system and brake-steer
TWI488429B (zh) * 2008-11-07 2015-06-11 Viasat Inc 具單一本地振盪器的雙轉換發射器
US8385855B2 (en) * 2008-11-07 2013-02-26 Viasat, Inc. Dual conversion transmitter with single local oscillator
US20100117693A1 (en) * 2008-11-07 2010-05-13 Viasat, Inc. Dual conversion transmitter with single local oscillator
WO2010082957A1 (en) * 2009-01-19 2010-07-22 Skyworks Solutions, Inc. Programmable transmit continuous-time filter
US8682263B2 (en) 2009-01-19 2014-03-25 Skyworks Solutions, Inc. Programmable transmit continuous-time filter
US9078215B2 (en) 2009-01-19 2015-07-07 Skyworks Solutions, Inc. Programmable transmit continuous-time filter
US9408154B2 (en) 2009-01-19 2016-08-02 Skyworks Solutions, Inc. Programmable transmit continuous-time filter
TWI502926B (zh) * 2013-08-05 2015-10-01 Hon Hai Prec Ind Co Ltd 雙工器及使用該雙工器的線纜數據機

Also Published As

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EP0469898B1 (en) 1996-03-20
CA2048148A1 (en) 1992-02-01
JP2595783B2 (ja) 1997-04-02
DE69118045T2 (de) 1996-10-02
AU635147B2 (en) 1993-03-11
DE69118045D1 (de) 1996-04-25
EP0469898A3 (en) 1992-08-12
JPH0487424A (ja) 1992-03-19
AU8151291A (en) 1992-02-06
CA2048148C (en) 1995-11-28
EP0469898A2 (en) 1992-02-05

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